Portable chain saw



Aug. 2, 1955 SMITH 2,714,406

PORTABLE CHAIN SAW Filed March 50', 1951 3 Sheets-Sheet 1 1 e E 1m IIH IT tBfld] INVENTOR DONALD J. sun-m mzkw ATTORN EY Aug. 2, 1955 D. J. SMITH PORTABLE CHAIN SAW 3 SheetsSheet 2 Filed March 50, 1951 R o T N E V N DONALD J SMITH 6M ATTORNEY 2, 1955 D. J. SMITH 4,406

PORTABLE CHAIN SAW INVENTOR DONALD J. SMITH ATTORNEY United States Patent PGRTABLE CHAIN SAW Donald J. Smith, Worcester, Mass, assignor to Reed- Prentice Corporation, Worcester, Mass., a corporation of Massachusetts Application March 30, 1951, Serial No. 218,379

Claims. (Cl. 14332) The present invention relates to chain saws of the portable type that are driven from the power developed by an internal combustion engine, with the entire mech' anism including the chain saw, engine and fuel tank being readily transportable to different locations for performing various kinds of sawing operations. Such portable power saws are widely used in lumbering under conditions in which it is often necessary for the operator to make cuts with the plane of the chain saw disposed at different angles from either the horizontal or vertical.

The object of the present invention is to provide an improved portable chain saw construction characterized by the fact that the saw and its engine are mounted as one unit, for pivotal movement with respect to a second unit comprising a fuel tank, carburetor and handles for carrying the saw and for controlling the operation of the engine. With this improved construction, it is possible to employ the saw for making cuts at any desired angle, while always maintaining the fuel tank and the carburetor in an upright position in which the fuel mixture is delivered to the engine through a swivel joint connecting the two units. As a result, the engine will drive the chain saw at any angle in which it is desired to make a cut, with the assurance that the fuel tank and the car buretor will remain in the same relative position, with the bottom of the fuel tank always disposed above the intake to the carburetor. A further feature of the present invention resides in the provision of means for supplying oil under pressure to the chain saw from a lubricant reservoir mounted beside the fuel tank, with the oil passing continuously through the swivel joint to the chain, in

any position of the engine and saw unit.

The above and other advantageous features of the present invention will hereinafter more fully appear from the following description, considered in connection with the accompanying drawings, in which,

Fig. l is a view in side elevation of a portable chain saw embodying the present invention.

Fig. 2 is a plan view of the saw shown in Fig. 1.

Fig. 3 is a view in side elevation showing the engine and saw unit turned about the swivel joint through an angle of 90, with relation to Fig. 1.

Fig. 4 is a plan view of the left-hand portion of the saw shown in Fig. 3.

Fig. 5 is a view in end elevation of the saw shown in Fig. 1, as viewed from the left.

Fig. 6 is a sectional view on an enlarged scale along the line 66- of Fig. 5, looking in the direction of the arrows, with the swivel adaptor for the engine and saw unit being partially shown.

Fig. 7 is a view in front elevation of the swivel adaptor for the engine and saw unit, with the engine in outline.

Fig. 8 is a fragmentary sectional view along the line 8-8 of Fig. 7, looking in the direction of the arrows.

Fig. 9 is a view in front elevation of the fuel tank and carburetor housing shown in Fig. 6, as viewed from the left.

Fig. 10 is a side view of the housing shown in Fig. 9,

"ice

2 and including the clamping device for the swivel joint between the units.

Fig. 11 is a fragmentary sectional view along the line l111 of Fig. 10, looking in the direction of the arrows.

Referring first to Figs. 1 and 2, a chain saw 1 consisting of pivotally connected cutter links 2 is mounted for sliding movement along a cutter bar 3, with the saw passing around sprockets 4 and 5 rotatably mounted at opposite ends of the cutter bar 3. The sprocket 4 is adapted to be driven by an internal combustion engine 6 through gearing 7 enclosed within a casing 8. The outer end of the cutter bar 3 carries a tail-stock 9 which serves to retatably support the sprocket 5, and provides a handle 9a by means of which the outer end of the saw can be held.

The saw 1, cutter bar 3 and engine 6 are assembled together as a unit which is capable of pivotal movement about the axis of a swivel connection, generally indicated by the reference character It). This swivel connection is interposed between the engine and saw unit and a second unit consisting of a fuel tank lit, a lubricant reservoir 33, a carburetor 13, see Fig. 5, and handles 14 which are so formed as to provide legs 15 for supporting the unit above the ground. By reason of the swivel connection 10 between the two units, it is possible to turn the saw and engine unit about the aXis of the swivel from the position of Fig. 1 into the position of Fig. 3, with the fuel tank 11 and the carburetor 13 remaining in an upright position, which can be maintained either by supporting the left-hand end of the saw by the outside handles 14, or. by resting the legs 15 on the ground.

Referring now to Fig. 6, the fuel tank 11 is shown as being formed as part of a housing 16 surrounding the carburetor 13, with the housing 16 also providing a swivel base 17 which closes one end of the housing. The base 17 provides a centrally located passage 18, and this passage is surrounded by a boss 19 to which the carburetor 13 is attached by bolts Ztl (see Fig. 9) passing through a flange 13a on the carburetor. Fuel is supplied to the carburetor 13 by a pipe 21 (see Fig. 5) leading from the bottom of the fuel tank ll and when the engine 6 is operating, the carburetor 13 will supply a fuel mixture directly to the passage 18 extending through the swivel base 17, under the control of a throttle valve 22, see Fig. I].

The swivel connection ll! also comprises an adaptor 23 which is attached to the crank case of the engine, as shown in Fig. 7, or may be formed integrally therewith. The swivel adaptor provides an annular projection 24 on its front face which closely fits upon a cylindrical hub portion 25 of the base 17 surrounding the passage 18. The adaptor 23 is, therefore, rotatably mounted on the base 17 and the two parts of the swivel connection are held together by a clamping member 26 which encircles flanges 27 and 28 formed on the base 17 and the adaptor 23, respectively, see Fig. 6. As best shown in Fig. 11, the clamping member 26 consists of a split ring, the ends of which provide lugs 29 that can be drawn together by a bolt 30 in order to ciamp the adaptor 23 in any desired angular position on the base 17 by the contraction of the ring 26, as will later be described.

The swivel adaptor 23 also provides an arm 31 which is attached to the crank case of the engine 6, as shown in Fig. '7. Therefore, the adaptor 23 serves to support the entire saw and engine unit upon the swivel base 17, with the entire unit being movable bodily about the axis of the swivel connection 10 to dispose the cutter bar in any desired plane. The adaptor 23 also serves to conduct the fuel mixture from the carburetor 13 directly to the fuel intake of the engine 6, and for this purpose provides a. passage 32 one end of which is in register with the end of the passage 13 in the base 17 when the adaptor plate 23 is mounted upon the hub 25, as shown in Fig. 8. Therefore, the passages 18 and 32 provide a continuous 3 conduit for conducting the fuel mixture directly from the carburetor 13 to the engine 6, in any position which the adaptor 23 and the saw and engine unit may occupy with respect to the axis of the swivel connection it As previously pointed out, the present invention also provides means for supplying lubricating oil to the chain 1 while the chain is being driven by the engine 6. For this purpose the housing 16 also carries the lubricant reservoir 33 which is located beside the fuel tank 11, as shown in Fig. 9. The reservoir extends below the swivel connection and the bottom of the reservoir provides a passage 34 which extends into the swivel base 17 and is in com munication with a second passage 35 extending through the base 17 and opening into an annular chamber 36 surrounding the hub 25, as best shown in Figs. 6 and 11. Therefore, oil from the reservoir 23 flow into the chamber 36 which also receives the projection 24 on the adaptor 23. In order to conduct this oil from the charm ber 36, a passage 37 is formed in the projection 24 which extends into a boss formed integrally with the swivel base 17, as shown in Fig. 7. A pipe 38 leads from this passage 37, with the pipe 38 being shown in Fig. l as leading to the cutter bar 3, so that oil can be supplied to the chain at a point adjacent to the sprocket 4, in any position of the swivel adaptor 23 with respect to the axis of the swivel connection 10.

In order to deliver oil under pressure from the reservoir 33 to the pipe 38, the reservoir provides a small handoperated air pump 39, the cylinder of which is received into an opening 40 provided at the top of the reservoir. The pump 39 provides a handle 41 by means of which it may be operated in order to build up air pressure with in the reservoir 33, which will force the oil through the passages 34, 35 and 37 to the pipe 38 leading to the chain saw 1. With this arrangement, a considerable quantity of oil is always present in the chamber 36 between the passages 35 and 37.

As previously pointed out, the handles 14 which are attached to the sides of the housing 16 enable the entire saw to be readily transported and held so that the carburetor 13 remains upright, while the cutter bar 3 and the engine 6 may be set in any desired angle with reference to the axis of the swivel connection 10. One handle 14 also serves to support a throttle lever 42 which is connected to the throttle valve 22 of the carburetor 13 by a flexible cable 43 extending through an opening 43a in the side of the housing 16, as best shown in Figs. 9 and 10. The end of the lever 42 is in a position for easy operation by the finger of an operator who is holding one of the handles 14, with the assurance that ready control of the engine speed through the throttle valve 22 will be obtained in any angular position of the cutter bar 3, due to the fact that the carburetor 13' remains upright and the position of the cable 43 is not affected by turning the saw and engine unit about the swivel axis.

The clamping member 26 which serves to hold the adaptor 23 on the swivel base 17, in any desired angular relation, can be operated from tank housing 16 by means of a locking handle 44 which provides a shaft 45 extending through the housing to engage a notch 46 formed on the head of the bolt 30 which serves to contract the clamping member 26 upon the flanges 27 and 28. The shaft 45 provides a cam surface 47, which in the position shown forces the lugs 29 together against pressure exerted on the lugs 29 by a spring 48 surrounding the bolt 30. Upon turning the handle 44 through 90, the spring 48 will spread the member 26 to the point where the adaptor 23 can be turned on the swivel base 17. After the cutter bar 3 has been turned about the swivel axis to present the cutter links 2 at the desired angle, the clamping member 26 can again be caused to grip the flanges 27 and 28 and lock the cutter bar in its adjusted position, by turning the handle 44 in the opposite direction, to cause the cam surface 27 to again draw the lugs 29 together, as shown in Fig. ll.

7 the engine.

. 4' From the foregoing it is apparent that by the present invention there is provided an improved portable chain saw which can be readily carried from place to place and can be adjusted to present the cutter bar at any desired angle to the surface of the work which is to be sawed. The fact that the saw and the engine for driving the same are mounted as one unit which can be turned about the swivel connection independently of the fuel tank and carburetor unit, insures an extremely effective operation of Since the carburetor remains in a substantially upright position during the operation of the saw at any angle, any desired setting of the throttle can be maintained, and the flow of fuel to the carburetor from the tank will also remain constant due to the fixed relation between the carburetor and the tank on the housing 16. Furthermore, the engine 6 can be swung in either direction about the axis of the swivel connection 10, without interfering with the flow of the fuel mixture from the carburetor to the motor intake through the passages 13 and 32, which remain in communication in any position of the swivel adaptor 23, and while maintaining a continuous supply of oil to the saw through the pipe 38.

I claim:

1. A portable chain saw comprising in combination, a first unit consisting of a chain saw and an internal combustion engine connected to said saw for driving the same, a second unit consisting of a fuel tank, a carburetor connected thereto, a lubricant reservoir, and means for supporting the unit with the fuel tank and carburetor in an upright position, a swivel connection between said units, means for clamping said swivel connection for supporting the saw and engine unit in any desired angular position with respect to the tank and carburetor unit, from which the fuel mixture passes to the engine through said swivel connection, and means for conducting lubricant from said reservoir through said swivel connection to a point on said saw.

2. A portable chain saw comprising in combination, a first unit consisting of a housing for enclosing a carburetor, with said housing being formed with separate fuel and lubricant tanks, a swivel base provided by said housing with a central passage leading from said carburetor, and with an annular chamber surrounding said passage and connected to the lubricant tank, means for supporting said housing with the carburetor in an upright position, and a second unit consisting of a chain saw and an internal combustion engine for driving said saw, with said second unit providing a swivel adaptor mounted on said engine and cooperating with said swivel base for supporting the saw and engine unit in any desired angular position about the swivel axis, while maintaining the flow of the fuel mixture between the carburetor and engine through the swivel passage and the flow of lubricant to the saw from the chamber in said swivel base.

3. A portable chain saw comprising in combination, a first unit consisting of a housing for enclosing a carburetor, with said housing being formed with separate fuel and lubricant tanks, a swivel base provided by said housing with a central passage leading from said carburetor, and with an annular chamber surrounding said passage and connected to the lubricant tank, means for supporting said housing with the carburetor in an upright position, and a second unit consisting of a chain saw and an internal combustion engine for driving said saw, with said second unit providing a swivel adaptor mounted on the crankcase of said engine and cooperating with said swivel base for supporting the saw and engine unit in any desired angular position about the swivel axis, while maintaining the flow of the fuel mixture between the carburetor and engine through the swivel passage and the flow of lubricant to the saw from the chamber in said swivel base and means for clamping said swivel base and adaptor together.'

4. A portable chain saw comprising in combination, a first unit consisting of a housing for enclosinga carburetor, with said housing being formed with separate fuel and lubricant tanks, a swivel base provided by said housing with a central passage leading from said carburetor, and with an annular chamber surrounding said passage and connected to the lubricant tank, means for supporting said housing with the carburetor in an upright position. and a second unit consisting of a chain saw and an internal combustion engine for driving said saw, with said second unit providing a swivel adaptor mounted on the crankcase of said engine and cooperating with said swivel base for supporting the saw and engine unit in any desired angular position about the swivel axis, while maintaining the flow of the fuel mixture between the carburetor and engine through the swivel passage and the flow of lubricant to the saw from the chamber in said swivel base and means mounted on said housing for clamping and unclamping said swivel base and adaptor.

5. A portable chain saw comprising in combination, a housing having a swivel base with a central passage extending therethrough, a carburetor mounted within said housing in communication with said passage, separate fuel and lubricant tanks mounted on said housing which also provides an annular chamber surrounding said passage and connected to said lubricant tank, means for supporting said housing with said carburetor and fuel and lubricant tanks in an upright position, a unit consisting of a chain saw and an internal combustion engine for driving said saw, said unit providing a swivel adaptor extending from said engine and cooperating with said swivel base, a clamping device in the form of a split ring enclosing said swivel base and adaptor for normally, holding the saw and engine unit in a predetermined angular relation about the swivel axis, while maintaining the flow of the fuel mixture between the carburetor and engine through the swivel passage and the fiow of lubricant to the saw from the chamber in the swivel base, and means mounted on said housing for releasing said clamping device to permit angular adjustment of said saw and engine unit on said housing.

References Cited in the file of this patent UNITED STATES PATENTS 635,286 Ambrose Oct. 24, 1899 882,574 Moukos Mar. 24, 1908 1,386,712 Leinweber Aug. 9, 1921 2,068,787 Baumgartner Jan. 26, 1937 2,370,556 Mall Feb. 27, 1945 2,487,322 Eriksson Nov. 8, 1949 2,630,844 Abbott et a1. Mar. 10, 1953 FOREIGN PATENTS 553,744 Germany June 30, 1932 124,146 Australia Apr. 24, 1947 

